A comprehensive study of 4,500 children conducted by the National Institutes of Health in 2018 shows that children who spent more than seven hours a day staring at screens showed evidence of premature thinning of their brain's cortex一the outer layer that processes sensory information. "We don't know if it
1． (cause) by the screen time. We don't know yet if it's a bad thing. It won't be until we follow them over time
2． we will see if there are outcomes that are associated with the differences that we're seeing in this single snapshot, Dr. Gaya Dowling. ^uWhat we can say is that this is
3．the brains look like of kids who spend a lot of time on screens. And it's not just one pattern."

The problem isn't just screens
4．, but also the way screens tempt kids (and adults) away from something far more important: physical activity. More than 23 percent of adults and 80 percent of adolescents don't get enough physical activity, and according to a 2019 report from the World Health Organization (WHO) , these patterns of activity and rest arise
5．habits we develop early in life. ^uWhat we really need to do is
6． (bring) back play for children," says Dr. Juana Willumsen, a WHO specialist in childhood obesity and physical activity, in a statement about new WHO guidelines issued in April 2019. “ This is about making the shift from sedentary time to playtime, while 
7． (protect) sleep. Of course, children aren't completely to blame for their screen addiction.

Sometimes, the parents
8．complain about the role of screens in family life are just as guilty of spending too much time in front of one. A 2016 study 
9． (conduct) by Common Sense Media found that parents spend up to nine hours a day in front of screens, mostly not for work-related reasons. While 78 percent of parents said they believed they were good screen time role models, the study found a disconnect between their behavior and their perception of their behavior. Parents need to limit screen time for themselves and especially for their kids一 
10． it means playing the bad guy. Our mental and physical health depends on it.

Some Very "American" Words Come from Chinese

Many of the Chinese words that are now part of English were borrowed long ago. They are most often from Cantonese(粤语)or other Chinese languages rather than Mandarin. Let's start with them.

kowtow

The English word kowtow is a verb that means to agree too easily to do what someone else wants you to do, or to obey someone with power in a way that seems
11．. It comes from the Cantonese word kau tau, which means " knock your head ”. It refers to the act of kneeling and lowering one's head as a sign of respect to
12． —such as emperors, elders and leaders. In the case of emperors, the act required the person to touch their head to the ground. Britain's Lord George Macartney refused to “kau tau" to the Qianlong Emperor. Soon after, the English word "kowtow" was born. In 1793, Britain's King George III sent Lord George Macartney and other trade ambassadors to China to
13． a trade agreement. The Chinese asked them to kowtow to the Qianlong Emperor. As the story goes, Lord Macartney refused for his
14．to do more than bend their knees. He said that was all they were required to do for their own king.

It is not surprising, then, that Macartney left China without negotiating the trade agreement. After that, critics used the word kowtow when anyone was too submissive to China. Today, the usage has no connection to China, nor any specific political connection.

gung-ho

Another borrowed word that came about through
15． between two nations is gung-ho. In English, the word gung-ho is an adjective that means extremely excited about doing something. The Chinese characters " gong" and " he" together mean " work together, cooperate. " The original term—gongyehezudshe—means Chinese Industrial Cooperatives. The organizations were established in the 1930s by Westerners in China to promote industrial and economic development. Lt. Colonel Evans Carlson of the United States Marine Corps observed these cooperatives while he was in China. He was impressed, saying "... all the soldiers
16．themselves to one idea and worked together to put that idea over. " He then began using the term gung-ho in the Marine Corps to try to create the same spirit he had
17．. In 1942, he used the word as a training slogan for the 2nd Marine Raider Battalion during World War II.The men were often called the “Gung Ho Battalion". From then, the word gung-ho spread as a slogan throughout the Marine Coips. Today, its meaning has no relation to the military.typhoon

In English, a typhoon is a very powerful and
18． storm that occurs around the China Sea and in the South Pacific. The word history of typhoon had a far less direct path to the English language than gung-ho. And not all historical accounts are the same. But, according to the Merriam-Webster New Book of Word Histories, the first typhoons reported in the English language were in India and were called " touffons" or "tufans".  The word tufan or al-tufan is Arabic and means violent storm or flood. The English came across this word in India and boiTowed it as touffon. Later, when English ships encountered violent storms in the China Sea, Englishmen learned the Cantonese word tai fung, which means great wind. ‘‘ The word's
19． to touffon is only by chance. The modern form of the word—typhoon—was influenced by the Cantonese but
20．to make it appear more Greek.

When 17-year-old Quattro Musser hangs out with friends, they don't drink beer or cruise around in cars with their dates. _____, they stick to G-rated activities such as rock- climbing or talking about books.

They are in good company, according to a new study showing that teenagers are increasingly delaying activities that had long been seen as rites of passage into _____. The study, published Tuesday in the journal Child Development, found that the percentage of adolescents in the U. S. who have a driver's license, who have tried alcohol, who date, and who work for pay has plummeted since 1976, with the most precipitous (急剧的) _____ in the past decade. The declines appeared across race, geographic, and socioeconomic lines, and in rural, urban, and suburban areas.

To be sure, more than half of teens still engage in these activities, but the _____ have slimmed considerably. Teens have also reported a steady decline in sexual activity in recent decades, as the portion of high school students who have had sex fell from 54 percent in 1991 to 41 percent in 2015, according to Centers for Disease Control statistics. ^u People say, 'Oh, it's because teenagers are more responsible, or more lazy, or more boring, ' but they're _____ the larger trend," said Jean Twenge, lead author of the study, which drew on seven large time-lag surveys of Americans. Rather, she said, kids may be less _____ in activities such as dating, driving or getting jobs because in today's society, they no longer need to.

According to an evolutionary psychology theory that a person's "life strategy" slows down or speeds up depending on his or her _____, exposure to a "harsh and unpredictable" environment leads to faster development, while a more resource-rich and secure environment has the _____ effect, the study said. In the first _____, "You'd have a lot of kids and be in survival mode, start having kids young, expect your kids will have kids young, and expect that there will be more _____and fewer resources, " said Twenge, a psychology professor at San Diego State University who is the author of "iGen： Why Today's Super- Connected Kids Are Growing Up Less Rebellious, More Tolerant, Less Happy-and Completely Unprepared for Adulthood."

In that model a teenage boy might be thinking more _____ about marriage, and driving a car and working for pay would be important for “ establishing mate value based on procurement of resources," the study said. But America is shifting more toward the _____model, and the change is apparent across the socioeconomic spectrum, Twenge said. ^uEven in families whose parents didn't have a college education. . . families are smaller, and the idea that children need to be carefully   _____ has really sunk in. ‘‘ The _____of ⁴¹ adult activities'' could not be attributed to more homework or extracurricular activities, the study said, noting that teens today spend fewer hours on homework and the same amount of time on extracurriculars as they did in the 1990 s (with the exception of community service, which has risen slightly). Nor could the use of smartphones and the Internet be entirely the _____, the report said, since the decline began before they were widely available. If the delay is to make room for creative exploration and forming better social and emotional connections, it is a good thing, he said.

   Bitcoin and other so-called cryptocurrencies （加密货币）have been all over the news lately. Apparently, the idea of money that's not tied to a specific bank—or a specific country—is appealing to many. But it's worth remembering that the banking system that we now all live with is just that： A modern invention. Not so long ago, money was almost always created and used locally, and bartering was common. （In fact, it still is common among many online local networks, like the Buy Nothing Project.）.

In the past, money's makeup varied from place to place, depending on what was considered valuable there. So while some of the world's first coins were made from a naturally occurring hybrid of gold and silver called electrum （银金矿），objects other than coins have served as currency, including beads, ivory, livestock, and cowrie shells. In West Africa, bracelets of bronze or copper were used as cash, especially if the transaction was associated with the slave trade there. Throughout the colonial period, tobacco was used to replace coins or paper bills in Virginia, Maryland and North Carolina, even though it was used elsewhere in the colonies and extensively throughout Europe and the U. K.

Today, on an island in the Pacific, a specific type of shell still serves as currency—and some people there are even hoarding（贮存）it, just like Bitcoin moguls, convinced that one day, it will make them wealthy beyond imagination. On Malaita, the most-populated island that's part of the Solomon Islands, shells are accepted at most places in exchange for goods.

"How much tuna（金枪鱼）you can get for your shells depends on their color and shape," Mary Bruno, a shop owner from the small town of Auki, on Malaita, told Vice. "One strip of darker shells might get you about two cans of smaller tuna, but the red ones are worth more. For the red ones, one strip might get enough tuna to feed a big family for a long time."

Just like a mint that creates coins, there's only one place on the island where the shells, which are polished and strung together to form 3-foot-long ropes, are made. The strips of red, white, and black shells all come from Langa Langa Lagoon, where artificial islands were long-ago built by locals to escape from the island-dwelling cannibals. Once marooned（困住）out on their islands, locals needed a currency to use among themselves, and so the shell currency was born.

Using shells for money was common throughout the Pacific islands as late as the early 1900s, but Malaita is unique in that they are still used today. And just like cryptocurrencies, there are those who think the islanders are smart to invest in this type of money, which is reported to have risen in value over the last three decades. It might seem strange to hoard a bunch of processed, strung-together shells, but what is a pile of dollars? Just a specially printed piece of paper and hemp that we've assigned value to—and probably less durable over time than those shells.

Moving a Giant

The logistics of excavating(挖掘)and relocating a town's century-old, living sequoia(红杉)tree. Inhabitants of Boise, Idaho, watched with trepidation earlier this year as the city's oldest, tallest resident moved two blocks. The 105-year-old sequoia tree serves as a local landmark, not only for its longevity but also because renowned naturalist and Sierra Club cofounder John Muir provided the original seedling. So, when Saint Luke's Health System found that the 10-story-tall conifer(针叶树)stood stood in the way of its planned hospital expansion, officials called tree-moving firm Environmental Design.

The Texas-based company has developed and patented scooping and lifting technology to move massive trees. Weighing in at more than 800,000 pounds, the Boise sequoia is its largest undertaking yet. "I (had) lost enough sleep over this," says David Cox, the company's Western region vice president—and that was before the hospital mentioned the tree's distinguished origin. Before the heavy lifting began, the team assessed the root system and dug a five-foot-deep cylinder, measuring 40 feet in diameter, around the trunk to protect all essential roots. After encapsulating the root ball in wire mesh, the movers allowed the tree to adapt to its new situation for seven months before relocating it. The illustration details what followed. —Leslie Nemo

1. Mark A. Merit and his team at Environmental Design installed underneath the root ball a platform of seven-inch-diameter, 44-foot-long steelbars and, just below the rods, a first set of uninflated airbags (shown in gray). The team also dug a shallow ramp.

2. In roughly 15 minutes, the movers inflated the airbags to about three feet in diameter to raise the root ball to the surface of the hole.

3. By underinflating the front bags, the team allowed the platform carrying the tree to roll up the ramp and out of the hole while staying level. A trailer hauled the tree along as team members removed the airbags from the back of the platform and replaced them in the front. They repeated the process until the tree arrived at the edge of its new home.

4. There a second set of partially inflated bags (shown in white) waited inside the hole. Soil surrounding the sequoia in its original location was relocated as well, because trees are more likely to survive a transplant when they move with their original soil.

5. Using the first set of airbags, the movers rolled the platform into the new hole.

6. The bags waiting there were then inflated further to take the weight of the sequoia while the transportation bags were deflated and removed from under the tree.

7. The white bags were then deflated in about half an hour to lower the sequoia's root ball to the bottom of its hole. The bags were removed, but the metal bars were left with the tree because they rust and degrade over a number of years.

8. For the next five years the local park service will monitor and maintain the tree in its new home.

   Understand the Economic Concept of a Budget Line

The term “budget line" has several related meanings, including a couple that are self-evident and a third that is not.

The Budget Line as an Informal Consumer Understanding

The budget line is an elementary concept that most consumers understand intuitively without a need for graphs and equations—it's the household budget, for example.

Taken informally, the budget line describes the boundary of affordability for a given budget and specific goods.

Given a limited amount of money, a consumer can only spend that same amount buying goods. If the consumer has X amount of money and wants to buy two goods A and B, she can only purchase goods totaling X. If the consumer needs an amount of A costing 0. 75 X, she can then spend only 0. 25 X, the amount remaining, on her purchase of B.

This seems almost too obvious to bother writing or reading about. As it turns out, however, this same concept——one that most consumers make many times each day with reflecting on it—is the basis of the more formal budget line concept in economics, which is explained below.

Lines in a Budget

Before turning to the economics definition of “budget line" , consider another concept: the line-item budget. This is effectively a map of future expenditures, with all the constituent expenditures individually noted and quantified. There's nothing very complicated about this； in this usage, a budget line is one of the lines in the budget, with the service or good to be purchased named and the cost quantified.

The Budget Line as an Economics Concept

One of the interesting ways the study of economics relates to human behavior generally is that a lot of economic theory is the formalization of the kind of simple concept outlined above— a consumer's informal understanding of the amount she has to spend and what that amount will buy.

In the process of formalization, the concept can be expressed as a mathematical equation that can be applied generally.

A Simple Budget Line Graph

To understand this, think of a graph where the vertical lines quantify how many movie tickets you can buy and where the horizontal lines do the same for crime novels. You like going to the movies and reading crime novels and you have $ 150 to spend. In the example below, assume that each movie costs $ 10 and each crime novel costs $ 15. The more formal economics term for these two items is budget set.

If movies cost $ 10 each, then the maximum number of movies you can see with the money available is 15. To note this you make a dot at the number 15 (for total movie tickets) at the extreme left-hand side of the chart. This same dot appears at the extreme left above "0" on the horizontal axis because you have no money left for books—the number of books available in this example is 0.

You can also graph the other extreme—all crime novels and no movies. Since crime novels in the example cost $ 15 and you have $ 150 available, if you spend all the available money crime novels, you can buy 10. So you put a dot on the horizontal axis at the number 10.

You'll place the dot at the bottom of the vertical axis because in this instance you have $ 0 available for movie tickets.

If you now draw a line from the highest, leftmost dot to the lowest, rightmost dot you'll have created a budget line. Any combination of movies and crime novels that falls below the budget line is affordable. Any combination above it is not.

Magazine Articles: More Valuable Than You May Think

Parents are often surprised when teachers suggest their children read magazines. Read on to learn about the benefits that reading magazines offers to young readers and how to introduce your children to the medium.

Magazine Benefits

Magazine articles can provide reluctant readers with a lively, breezy writing style that can inspire them to read more.

The articles in magazines are generally short, which allows a child to finish reading a feature article without losing interest due to a short attention span. The writing in magazines also tends to be easy to read, especially if it is a children's publication.

By allowing your child to read magazines at an early age, you are encouraging development of a useful skill.
47．Getting into the habit of reading periodicals as a child will foster the habit of reading news articles that may continue into adulthood.

48． Magazine articles challenge students to think about issues they may have never considered or cause them to rethink their world view. Information is available in a wide variety of reading levels because magazines are written for every audience imaginable. Many publications cover the same material in different writing styles that might make it easier for your child to comprehend.

Magazine Activities

Reading magazines as a family can be used to introduce each other to the various interests that each family member possesses. When your children are finished with their magazines, encourage them to pass their issue on to a sibling or other family member.

Once each family member has finished reading each magazine, you can use them for art and writing projects. These projects are for family members of all ages:

1. Cut out pictures to help your preschool and kindergarten children learn their alphabet, numbers, and colors.

2.
49． Paste the picture at the top of a page and have them write a story about what is happening or what the picture represents.

3. Clip pictures to create a collage. Many teenagers love using their artistic talents to collage.

50．The skills that students utilize and strengthen when reading magazines can be applied to higher level reading and other academic subjects. Encouraging your child to read by giving them a magazine subscription could cause them to take the leap from being a reluctant N reader to a voracious page-turner.

Becoming an Attractive Employee

The 2008 financial crisis created an unstable job market. Fast-forward to the present, and the economy has not fully recovered. Thus, it^’s of vital importance for job seekers to carefully strategize their approach to job application. And it’s especially important for those new to the work force. They should look at making themselves as attractive as possible to employers.

For young people, information technology skills will play an increasing role in the future. As the generation to have grown up in the Information Age, they are quite confident when it comes to showing off their interests and skills in this field. This makes them a natural fit for companies seeking expertise(专业技能)in technology, marketing and networking. They should emphasize these skills when applying for jobs that require the ability to multitask.

Another attractive quality is experience. It is important that an applicant's resume list any activities that involved teamwork and goal-driven responsibilities. Membership in a sports or social club and participation as a volunteer are good examples of this. These activities involve goal management and planning along with the ability to focus while competing on a team. When hiring committees see this, they see a candidate who is capable of working in a variety of environments.

Finally, an attractive quality when job-hunting is a great attitude toward a potential job. Young job seekers are known to be overconfident because they have been praised for everything they have done. But they must realize that the employment market is about how an employee will be a good fit for a company, not the other way around.

In fact, in an interview, an important question to ask is: "What would be expected of me as an employee?" In today's tough job market, young job seekers need to provide a potential employer with good reasons to hire them.